SurfaceView

package com.example.homework;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.Manifest;
import android.content.pm.PackageManager;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.media.MediaPlayer;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.Window;
import android.widget.SeekBar;

import com.example.homework.bean.Music;
import com.example.homework.bean.MusicBean;
import com.google.gson.Gson;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;

public class Main2Activity extends AppCompatActivity implements SurfaceHolder.Callback{

private static final String TAG = "MainActivity";
private SurfaceView mSurfaceView;
private SeekBar mSeekBar;
private MediaPlayer mediaPlayer;
private SurfaceHolder holder;
private List<Music> list=new ArrayList<>();
private Timer timer=new Timer();
private int position;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_main);

    initermission();

    initView();

    initData();

    initPlay();

    initSeekBarOnClick();
}

private void initSeekBarOnClick() {
    mSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
        @Override
        public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
            if(b){
                list.get(i).getText();
                mediaPlayer.seekTo(i);
            }
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {

        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {

        }
    });
}

private void initData() {

    try {
        FileInputStream is = new FileInputStream("/sdcard/Music/最炫民族风");
        int len=0;
        byte[] bytes = new byte[1024];
        StringBuffer sb = new StringBuffer();

        while ((len=is.read(bytes)) != -1) {

            sb.append(new String(bytes,0,len));

        }
        MusicBean musicBean = new Gson().fromJson(sb.toString(), MusicBean.class);
        String lyric = musicBean.getLrc().getLyric();

        String[] strings = lyric.split("\n");
        for (int i = 1; i < strings.length; i++) {
            String replace = strings[i].replace("[", "")
                    .replace(":","@")
                    .replace(".","@")
                    .replace("]","@");
            Log.i(TAG, "initData: "+replace);
            String[] split = replace.split("@");
            long  time=Integer.parseInt(split[0])*60*1000+Integer.parseInt(split[1])*1000+Integer.parseInt(split[2]);
            if (split.length>=4) {
            list.add(new Music(split[3],time));
            }
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

private void initermission() {
    if(Build.VERSION.SDK_INT>= Build.VERSION_CODES.M){
        requestPermissions(new String[]{
                Manifest.permission.READ_EXTERNAL_STORAGE,
                Manifest.permission.WRITE_EXTERNAL_STORAGE
        },120);
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if(requestCode==120&grantResults[0]== PackageManager.PERMISSION_GRANTED){
        Log.i(TAG, "onRequestPermissionsResult: 授权成功!");
    }else{
        Log.i(TAG, "onRequestPermissionsResult: 授权失败!");
    }
}

private void initPlay() {
    if(mediaPlayer==null){
        mediaPlayer=new MediaPlayer();
    }
    try {
        mediaPlayer.setDataSource("/mnt/sdcard/Music/凤凰传奇 - 最炫民族风(Live).mp3");
        mediaPlayer.prepareAsync();
        mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
            @Override
            public void onPrepared(final MediaPlayer mediaPlayer) {
                mediaPlayer.start();
                mSeekBar.setMax(mediaPlayer.getDuration());
                timer.schedule(new TimerTask() {
                    @Override
                    public void run() {
                        if(list.size()>=0&&position+1<list.size()){
                        int currentPosition = mediaPlayer.getCurrentPosition();
                        if(currentPosition>=list.get(position+1).getTime()){
                            position++;
                        }
                        mSeekBar.setProgress(currentPosition);
                        }
                    }
                },0,1000);
            }
        });
    } catch (IOException e) {
        e.printStackTrace();
    }
}

private void initView() {
    mSurfaceView = findViewById(R.id.surfaceView);
    mSeekBar = findViewById(R.id.seekBar);
    holder = mSurfaceView.getHolder();
    holder.addCallback(this);
}

@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {

    new MyThread().start();
}

@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {

}

@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {

}
class MyThread extends Thread{
    @Override
    public void run() {
        super.run();
        Paint paint = new Paint();
        paint.setTextSize(60);
        paint.setColor(Color.RED);
        paint.setStrokeWidth(10);
        paint.setAntiAlias(true);
        while(true){
            Canvas canvas = holder.lockCanvas();

            canvas.drawColor(Color.WHITE);
            canvas.drawText(list.get(position).getText(),200,400,paint);

            holder.unlockCanvasAndPost(canvas);
        }
    }
}

}